From the general state of the art, for the purpose of influencing the flight state of an aircraft, it is known, in addition to usual control flaps, to use additional flaps. Of such additional flaps on an aircraft, basically the use of flaps is known that are used as pure additional drag generators or that are used to generate forces and moments.
Flaps that serve as pure drag generators are used for improved glide path control or for faster or enhanced deceleration of the aircraft either in the air or on the ground after touchdown. For example, spoilers and speed brakes that are arranged on the wing are known. Likewise, spoilers arranged on the wing, apart from their function as control devices such as flaps, are also used to reduce wing uplift and as speed brakes. Moreover, in the Space Shuttle a split rudder is used. On the aircraft types BAe 146/AVRO RJ, Blackburn B103 Buccaneer and Fokker F70/100, split flaps, arranged at the tail, are used as speed brakes.
Flaps that are provided to generate forces and moments are used to supplement the usual control flaps for controlling the aircraft. The use of such additional flaps is advantageous in the way that they directly and quickly generate forces while at the same time preventing force couplings and/or moment couplings (coupling derivatives). To this effect, generally speaking, unilaterally deflected flaps for direct force control are known, which in particular can be arranged on the aircraft such that they are blown at by the engine jet, or are not blown at by the engine jet. Such solutions are associated with a disadvantage in that they involve significant construction expenditure while at the same time providing low efficiency. Moreover, it must be taken into account that the implementation of such elements for the sole direct force control places great demands on pilots and even more so on passenger comfort. This type of control element is therefore predominantly used in the design of fighter aircraft; for example it is used in the F16.